<?php
////////////////////////////////////////////////////
// SMTP - PHP SMTP class
//
// Version 1.02
//
// Define an SMTP class that can be used to connect
// and communicate with any SMTP server. It implements
// all the SMTP functions defined in RFC821 except TURN.
//
// Author: Chris Ryan
//
// License: LGPL, see LICENSE
////////////////////////////////////////////////////

/**
 * SMTP is rfc 821 compliant and implements all the rfc 821 SMTP
 * commands except TURN which will always return a not implemented
 * error. SMTP also provides some utility methods for sending mail
 * to an SMTP server.
 * @package PHPMailer
 * @author Chris Ryan
 */

# $Id$

class SMTP
{
	/**
	 *  SMTP server port
	 *  @var int
	 */
	var $SMTP_PORT = 25;
	
	/**
	 *  SMTP reply line ending
	 *  @var string
	 */
	var $CRLF = "\r\n";
	
	/**
	 *  Sets whether debugging is turned on
	 *  @var bool
	 */
	var $do_debug;	   # the level of debug to perform

	/**#@+
	 * @access private
	 */
	var $smtp_conn;	  # the socket to the server
	var $error;		  # error if any on the last call
	var $helo_rply;	  # the reply the server sent to us for HELO
	/**#@-*/

	/**
	 * Initialize the class so that the data is in a known state.
	 * @access public
	 * @return void
	 */
	function SMTP() {
		$this->smtp_conn = 0;
		$this->error = null;
		$this->helo_rply = null;

		$this->do_debug = 0;
	}

	/*************************************************************
	 *					CONNECTION FUNCTIONS				  *
	 ***********************************************************/

	/**
	 * Connect to the server specified on the port specified.
	 * If the port is not specified use the default SMTP_PORT.
	 * If tval is specified then a connection will try and be
	 * established with the server for that number of seconds.
	 * If tval is not specified the default is 30 seconds to
	 * try on the connection.
	 *
	 * SMTP CODE SUCCESS: 220
	 * SMTP CODE FAILURE: 421
	 * @access public
	 * @return bool
	 */
	function Connect($host,$port=0,$tval=30) {
		# set the error val to null so there is no confusion
		$this->error = null;

		# make sure we are __not__ connected
		if ($this->connected()) {
			# ok we are connected! what should we do?
			# for now we will just give an error saying we
			# are already connected
			$this->error = array('error' => 'Already connected to a server');
			return false;
		}

		if (empty($port)) { $port = $this->SMTP_PORT; }

		#connect to the smtp server
		$this->smtp_conn = fsockopen($host,	# the host of the server
									 $port,	# the port to use
									 $errno,   # error number if any
									 $errstr,  # error message if any
									 $tval);   # give up after ? secs
		# verify we connected properly
		if (empty($this->smtp_conn)) {
			$this->error = array('error' => 'Failed to connect to server',
								 'errno' => $errno,
								 'errstr' => $errstr);
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": $errstr ($errno)".$this->CRLF;
			}
			return false;
		}

		# sometimes the SMTP server takes a little longer to respond
		# so we will give it a longer timeout for the first read
		// Windows still does not have support for this timeout function
		if (!WINDOWS) { socket_set_timeout($this->smtp_conn, $tval, 0); }

		# get any announcement stuff
		$announce = $this->get_lines();

		# set the timeout  of any socket functions at 1/10 of a second
		//if (function_exists("socket_set_timeout"))
		//   socket_set_timeout($this->smtp_conn, 0, 100000);

		if ($this->do_debug >= 2) {
			echo "SMTP -> FROM SERVER:".$this->CRLF.$announce;
		}

		return true;
	}

	/**
	 * Performs SMTP authentication.  Must be run after running the
	 * Hello() method.  Returns true if successfully authenticated.
	 * @access public
	 * @return bool
	 */
	function Authenticate($username, $password) {
		// Start authentication
		fputs($this->smtp_conn,'AUTH LOGIN'.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($code != 334) {
			$this->error =
				array('error' => 'AUTH not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		// Send encoded username
		fputs($this->smtp_conn, base64_encode($username).$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($code != 334) {
			$this->error =
				array('error' => 'Username not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		// Send encoded password
		fputs($this->smtp_conn, base64_encode($password).$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($code != 235) {
			$this->error =
				array('error' => 'Password not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		return true;
	}

	/**
	 * Returns true if connected to a server otherwise false
	 * @access private
	 * @return bool
	 */
	function Connected() {
		if (!empty($this->smtp_conn)) {
			$sock_status = socket_get_status($this->smtp_conn);
			if ($sock_status['eof']) {
				# hmm this is an odd situation... the socket is
				# valid but we aren't connected anymore
				if ($this->do_debug >= 1) {
					echo "SMTP -> NOTICE:".$this->CRLF."EOF caught while checking if connected";
				}
				$this->Close();
				return false;
			}
			return true; # everything looks good
		}
		return false;
	}

	/**
	 * Closes the socket and cleans up the state of the class.
	 * It is not considered good to use this function without
	 * first trying to use QUIT.
	 * @access public
	 * @return void
	 */
	function Close() {
		$this->error = null; # so there is no confusion
		$this->helo_rply = null;
		if (!empty($this->smtp_conn)) {
			# close the connection and cleanup
			fclose($this->smtp_conn);
			$this->smtp_conn = 0;
		}
	}


	/***************************************************************
	 *						SMTP COMMANDS					   *
	 *************************************************************/

	/**
	 * Issues a data command and sends the msg_data to the server
	 * finializing the mail transaction. $msg_data is the message
	 * that is to be send with the headers. Each header needs to be
	 * on a single line followed by a <CRLF> with the message headers
	 * and the message body being seperated by and additional <CRLF>.
	 *
	 * Implements rfc 821: DATA <CRLF>
	 *
	 * SMTP CODE INTERMEDIATE: 354
	 *	 [data]
	 *	 <CRLF>.<CRLF>
	 *	 SMTP CODE SUCCESS: 250
	 *	 SMTP CODE FAILURE: 552,554,451,452
	 * SMTP CODE FAILURE: 451,554
	 * SMTP CODE ERROR  : 500,501,503,421
	 * @access public
	 * @return bool
	 */
	function Data($msg_data) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Data() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'DATA'.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 354) {
			$this->error =
				array('error' => 'DATA command not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		# the server is ready to accept data!
		# according to rfc 821 we should not send more than 1000
		# including the CRLF
		# characters on a single line so we will break the data up
		# into lines by \r and/or \n then if needed we will break
		# each of those into smaller lines to fit within the limit.
		# in addition we will be looking for lines that start with
		# a period '.' and append and additional period '.' to that
		# line. NOTE: this does not count towards are limit.

		# normalize the line breaks so we know the explode works
		$msg_data = str_replace("\r\n","\n",$msg_data);
		$msg_data = str_replace("\r","\n",$msg_data);
		$lines = explode("\n",$msg_data);

		# we need to find a good way to determine is headers are
		# in the msg_data or if it is a straight msg body
		# currently I'm assuming rfc 822 definitions of msg headers
		# and if the first field of the first line (':' sperated)
		# does not contain a space then it _should_ be a header
		# and we can process all lines before a blank "" line as
		# headers.
		$field = substr($lines[0],0,strpos($lines[0],':'));
		$in_headers = false;
		if (!empty($field) && !strstr($field,' ')) { $in_headers = true; }

		$max_line_length = 998; # used below; set here for ease in change

		foreach ($lines as $line) {
			$lines_out = null;
			if ($line == '' && $in_headers) { $in_headers = false; }
			# ok we need to break this line up into several smaller lines
			while(strlen($line) > $max_line_length) {
				$pos = strrpos(substr($line,0,$max_line_length),' ');
				# ----- Vulnerability fix (phpsec) -------
				if (!$pos) { $pos = $max_line_length - 1; }
				# --------- End of fix ----------------
				$lines_out[] = substr($line,0,$pos);
				$line = substr($line,$pos + 1);
				# if we are processing headers we need to add a LWSP-char to
				# the front of the new line rfc 822 on long msg headers
				if ($in_headers) { $line = "\t".$line; }
			}
			$lines_out[] = $line;

			# now send the lines to the server
			foreach ($lines_out as $line_out) {
				if (strlen($line_out) > 0) {
					if (substr($line_out, 0, 1) == '.') { $line_out = '.'.$line_out; }
				}
				fputs($this->smtp_conn,$line_out.$this->CRLF);
			}
		}

		# ok all the message data has been sent so lets get this
		# over with aleady
		fputs($this->smtp_conn, $this->CRLF.'.'.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) { echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply; }

		if ($code != 250) {
			$this->error =
				array('error' => 'DATA not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return true;
	}

	/**
	 * Expand takes the name and asks the server to list all the
	 * people who are members of the _list_. Expand will return
	 * back and array of the result or false if an error occurs.
	 * Each value in the array returned has the format of:
	 *	 [ <full-name> <sp> ] <path>
	 * The definition of <path> is defined in rfc 821
	 *
	 * Implements rfc 821: EXPN <SP> <string> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE FAILURE: 550
	 * SMTP CODE ERROR  : 500,501,502,504,421
	 * @access public
	 * @return string array
	 */
	function Expand($name) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Expand() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'EXPN '.$name.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) { echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply; }

		if ($code != 250) {
			$this->error =
				array('error' => 'EXPN not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		# parse the reply and place in our array to return to user
		$entries = explode($this->CRLF,$rply);
		while (list(,$l) = each($entries)) { $list[] = substr($l,4); }

		return $list;
	}

	/**
	 * Sends the HELO command to the smtp server.
	 * This makes sure that we and the server are in
	 * the same known state.
	 *
	 * Implements from rfc 821: HELO <SP> <domain> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE ERROR  : 500, 501, 504, 421
	 * @access public
	 * @return bool
	 */
	function Hello($host='') {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Hello() without being connected');
			return false;
		}

		# if a hostname for the HELO wasn't specified determine
		# a suitable one to send
		if (empty($host)) {
			# we need to determine some sort of appopiate default
			# to send to the server
			$host = 'localhost';
		}

		// Send extended hello first (RFC 2821)
		if (!$this->SendHello('EHLO', $host) && !$this->SendHello('HELO', $host)) { return false; }

		return true;
	}

	/**
	 * Sends a HELO/EHLO command.
	 * @access private
	 * @return bool
	 */
	function SendHello($hello, $host) {
		fputs($this->smtp_conn, $hello.' '.$host.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) { echo 'SMTP -> FROM SERVER: '.$this->CRLF.$rply; }

		if ($code != 250) {
			$this->error =
				array('error' => $hello.' not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		$this->helo_rply = $rply;
		
		return true;
	}

	/**
	 * Gets help information on the keyword specified. If the keyword
	 * is not specified then returns generic help, ussually contianing
	 * A list of keywords that help is available on. This function
	 * returns the results back to the user. It is up to the user to
	 * handle the returned data. If an error occurs then false is
	 * returned with $this->error set appropiately.
	 *
	 * Implements rfc 821: HELP [ <SP> <string> ] <CRLF>
	 *
	 * SMTP CODE SUCCESS: 211,214
	 * SMTP CODE ERROR  : 500,501,502,504,421
	 * @access public
	 * @return string
	 */
	function Help($keyword='') {
		$this->error = null; # to avoid confusion

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Help() without being connected');
			return false;
		}

		$extra = '';
		if (!empty($keyword)) { $extra = ' '.$keyword; }

		fputs($this->smtp_conn,'HELP'.$extra.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 211 && $code != 214) {
			$this->error =
				array('error' => 'HELP not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		return $rply;
	}

	/**
	 * Starts a mail transaction from the email address specified in
	 * $from. Returns true if successful or false otherwise. If True
	 * the mail transaction is started and then one or more Recipient
	 * commands may be called followed by a Data command.
	 *
	 * Implements rfc 821: MAIL <SP> FROM:<reverse-path> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE SUCCESS: 552,451,452
	 * SMTP CODE SUCCESS: 500,501,421
	 * @access public
	 * @return bool
	 */
	function Mail($from) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Mail() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'MAIL FROM:<'.$from.'>'.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) { echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply; }

		if ($code != 250) {
			$this->error =
				array('error' => 'MAIL not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return true;
	}

	/**
	 * Sends the command NOOP to the SMTP server.
	 *
	 * Implements from rfc 821: NOOP <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE ERROR  : 500, 421
	 * @access public
	 * @return bool
	 */
	function Noop() {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Noop() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'NOOP'.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 250) {
			$this->error =
				array('error' => 'NOOP not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return true;
	}

	/**
	 * Sends the quit command to the server and then closes the socket
	 * if there is no error or the $close_on_error argument is true.
	 *
	 * Implements from rfc 821: QUIT <CRLF>
	 *
	 * SMTP CODE SUCCESS: 221
	 * SMTP CODE ERROR  : 500
	 * @access public
	 * @return bool
	 */
	function Quit($close_on_error=true) {
		$this->error = null; # so there is no confusion

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Quit() without being connected');
			return false;
		}

		# send the quit command to the server
		fputs($this->smtp_conn,'quit'.$this->CRLF);

		# get any good-bye messages
		$byemsg = $this->get_lines();

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$byemsg;
		}

		$rval = true;
		$e = null;

		$code = substr($byemsg,0,3);
		if ($code != 221) {
			# use e as a tmp var cause Close will overwrite $this->error
			$e = array('error' => 'SMTP server rejected quit command',
					   'smtp_code' => $code,
					   'smtp_rply' => substr($byemsg,4));
			$rval = false;
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$e["error"].": ".$byemsg.$this->CRLF;
			}
		}

		if (empty($e) || $close_on_error) {
			$this->Close();
		}

		return $rval;
	}

	/**
	 * Sends the command RCPT to the SMTP server with the TO: argument of $to.
	 * Returns true if the recipient was accepted false if it was rejected.
	 *
	 * Implements from rfc 821: RCPT <SP> TO:<forward-path> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250,251
	 * SMTP CODE FAILURE: 550,551,552,553,450,451,452
	 * SMTP CODE ERROR  : 500,501,503,421
	 * @access public
	 * @return bool
	 */
	function Recipient($to) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Recipient() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'RCPT TO:<'.$to.'>'.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 250 && $code != 251) {
			$this->error =
				array('error' => 'RCPT not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return true;
	}

	/**
	 * Sends the RSET command to abort and transaction that is
	 * currently in progress. Returns true if successful false
	 * otherwise.
	 *
	 * Implements rfc 821: RSET <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE ERROR  : 500,501,504,421
	 * @access public
	 * @return bool
	 */
	function Reset() {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Reset() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'RSET'.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 250) {
			$this->error =
				array('error' => 'RSET failed',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}

		return true;
	}

	/**
	 * Starts a mail transaction from the email address specified in
	 * $from. Returns true if successful or false otherwise. If True
	 * the mail transaction is started and then one or more Recipient
	 * commands may be called followed by a Data command. This command
	 * will send the message to the users terminal if they are logged
	 * in.
	 *
	 * Implements rfc 821: SEND <SP> FROM:<reverse-path> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE SUCCESS: 552,451,452
	 * SMTP CODE SUCCESS: 500,501,502,421
	 * @access public
	 * @return bool
	 */
	function Send($from) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Send() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'SEND FROM:'.$from.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 250) {
			$this->error =
				array('error' => 'SEND not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return true;
	}

	/**
	 * Starts a mail transaction from the email address specified in
	 * $from. Returns true if successful or false otherwise. If True
	 * the mail transaction is started and then one or more Recipient
	 * commands may be called followed by a Data command. This command
	 * will send the message to the users terminal if they are logged
	 * in and send them an email.
	 *
	 * Implements rfc 821: SAML <SP> FROM:<reverse-path> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE SUCCESS: 552,451,452
	 * SMTP CODE SUCCESS: 500,501,502,421
	 * @access public
	 * @return bool
	 */
	function SendAndMail($from) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called SendAndMail() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'SAML FROM:'.$from.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 250) {
			$this->error =
				array('error' => 'SAML not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return true;
	}

	/**
	 * Starts a mail transaction from the email address specified in
	 * $from. Returns true if successful or false otherwise. If True
	 * the mail transaction is started and then one or more Recipient
	 * commands may be called followed by a Data command. This command
	 * will send the message to the users terminal if they are logged
	 * in or mail it to them if they are not.
	 *
	 * Implements rfc 821: SOML <SP> FROM:<reverse-path> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE SUCCESS: 552,451,452
	 * SMTP CODE SUCCESS: 500,501,502,421
	 * @access public
	 * @return bool
	 */
	function SendOrMail($from) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called SendOrMail() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'SOML FROM:'.$from.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 250) {
			$this->error =
				array('error' => 'SOML not accepted from server',
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return true;
	}

	/**
	 * This is an optional command for SMTP that this class does not
	 * support. This method is here to make the RFC821 Definition
	 * complete for this class and __may__ be implimented in the future
	 *
	 * Implements from rfc 821: TURN <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250
	 * SMTP CODE FAILURE: 502
	 * SMTP CODE ERROR  : 500, 503
	 * @access public
	 * @return bool
	 */
	function Turn() {
		$this->error = array('error' => 'This method, TURN, of the SMTP is not implemented');
		if ($this->do_debug >= 1) {
			echo 'SMTP -> NOTICE: '.$this->error['error'].$this->CRLF;
		}
		return false;
	}

	/**
	 * Verifies that the name is recognized by the server.
	 * Returns false if the name could not be verified otherwise
	 * the response from the server is returned.
	 *
	 * Implements rfc 821: VRFY <SP> <string> <CRLF>
	 *
	 * SMTP CODE SUCCESS: 250,251
	 * SMTP CODE FAILURE: 550,551,553
	 * SMTP CODE ERROR  : 500,501,502,421
	 * @access public
	 * @return int
	 */
	function Verify($name) {
		$this->error = null; # so no confusion is caused

		if (!$this->connected()) {
			$this->error = array('error' => 'Called Verify() without being connected');
			return false;
		}

		fputs($this->smtp_conn,'VRFY '.$name.$this->CRLF);

		$rply = $this->get_lines();
		$code = substr($rply,0,3);

		if ($this->do_debug >= 2) {
			echo 'SMTP -> FROM SERVER:'.$this->CRLF.$rply;
		}

		if ($code != 250 && $code != 251) {
			$this->error =
				array('error' => "VRFY failed on name '$name'",
					  'smtp_code' => $code,
					  'smtp_msg' => substr($rply,4));
			if ($this->do_debug >= 1) {
				echo "SMTP -> ERROR: ".$this->error["error"].": ".$rply.$this->CRLF;
			}
			return false;
		}
		return $rply;
	}

	/*******************************************************************
	 *					   INTERNAL FUNCTIONS					   *
	 ******************************************************************/

	/**
	 * Read in as many lines as possible
	 * either before eof or socket timeout occurs on the operation.
	 * With SMTP we can tell if we have more lines to read if the
	 * 4th character is '-' symbol. If it is a space then we don't
	 * need to read anything else.
	 * @access private
	 * @return string
	 */
	function get_lines() {
		$data = '';
		while ($str = fgets($this->smtp_conn,515)) {
			if ($this->do_debug >= 4) {
				echo "SMTP -> get_lines(): \$data was \"$data\"".$this->CRLF;
				echo "SMTP -> get_lines(): \$str is \"$str\"".$this->CRLF;
			}
			$data .= $str;
			if ($this->do_debug >= 4) {
				echo "SMTP -> get_lines(): \$data is \"$data\"".$this->CRLF;
			}
			# if the 4th character is a space then we are done reading
			# so just break the loop
			if (substr($str,3,1) == ' ') { break; }
		}
		return $data;
	}

}
